Spinal implants are often used in the surgical treatment of spinal disorders such as degenerative disc disease, disc herniations, curvature abnormalities, and trauma. Many different types of treatments are used. In some cases, spinal fusion is indicated to inhibit relative motion between vertebral bodies. In other cases, dynamic implants are used to preserve motion between vertebral bodies. In yet other cases, relatively static implants that exhibit some degree of flexibility may be inserted between vertebral bodies.
Implants such as these may be positioned between vertebral bodies, with superior and inferior surfaces placed in contact with the vertebral bodies. Often, the bone-contact surfaces of these implants are configured with a surface texture, surface features, and natural or synthetic bone growth stimulators to promote osseointegration of the implant. The quality of the interface between a vertebral implant and a vertebral body may affect the integrity and strength of the bond that forms between the vertebral body and the implant. Ineffective fusion at the bone-contact surface may lead to subsidence of the vertebral implants over time, and often leads to spinal instability, angular deformities, and planar translations.
One conventional approach uses mechanical means to prepare the surface of a vertebral body prior to inserting the vertebral implant. For example, the vertebral body could be planed or otherwise prepared to mate with a corresponding surface of an implant. However, this process of preparing the bone for implant insertion thins the vertebral endplates and has the potential to compromise the strength of the vertebral body. The bone preparation step also adds time to the procedure and trauma to the patient. Therefore, certain conventional vertebral implants are not configured to take advantage of the natural anatomy of vertebral bodies so as to eliminate or reduce this bone preparation step.